But Australian policy on nuclear weapons is hopelessly conflicted. With one hand, it promotes nuclear disarmament, yet with the other, it clings anxiously to US nuclear weapons for national security. Australia wants to get rid of nuclear weapons and keep them too.

There is no secret about this: Bishop wrote in February that Australia “has long and actively supported nuclear disarmament … and worked tirelessly toward the goal of a world free of nuclear weapons” and also that Australia “will continue to rely on nuclear deterrence” for its security as long as nuclear weapons exist. She is the latest custodian of a bipartisan policy that has been passed down through consecutive governments for decades.

As long as nothing much was happening with nuclear disarmament, Australia could safely advocate it. But the emergence of a global movement to examine the humanitarian consequences of nuclear weapons, and a related push for a treaty banning them, has put Australia on the spot.

International conferences held in Oslo last year and in Nayarit, Mexico, in February concluded that any nuclear detonation would completely overwhelm humanitarian and disaster response capabilities, and cause unacceptable long-term harm worldwide.

Australia cautiously participated in these meetings, but clearly with misgiving. And at the United Nations last October, when 125 countries, including Japan and five other NPDI members, made a joint statement on the humanitarian consequences of nuclear weapons, Australia baulked – and weaselled out.

Pressed to explain why Australia could not join the statement, officials said the sentence, “It is in the interest of the very survival of humanity that nuclear weapons are never used again, under any circumstances,” was incompatible with Australia’s reliance on nuclear deterrence.

Calls for a new treaty to ban nuclear weapons have further exposed the contradictions in Australia’s policy. There is no legal reason Australia could not join such a treaty tomorrow: Australia has no nuclear weapons. As a member of the Nuclear Non-proliferation Treaty (NPT) it has sworn off them.

The official response, however, has been to oppose such a ban because it would not “guarantee” nuclear disarmament. This is a ludicrous excuse, given that none of the approaches Australia and the NPDI advocate will “guarantee” disarmament either (in fact most of them are hopelessly bogged down).

That a polished performer like Bishop would field such a flimsy rationalisation only shows how bare the intellectual cupboard at the Foreign Ministry is. They can’t find a better argument, because there isn’t one.

Despite the increasing visibility of its inherently contradictory policy, the government blithely continues to seek a high profile on nuclear disarmament.

The people of Hiroshima will surely welcome Bishop’s earnest undertakings to address the humanitarian impact of nuclear weapons and pursue nuclear disarmament. They will be less impressed by her extraordinary statement that “the horrendous humanitarian consequences of nuclear weapons are precisely why deterrence has worked” – in other words, that Australia depends for its security on the very humanitarian consequences it claims to be working to avoid.The contradictions emerge even within the NPDI. The purpose of the NPDI is to support implementation of the 64-point “action plan” on non-proliferation and disarmament agreed by the 189 members of the NPT. Australia is a prominent proponent of the plan. But the very first of these 64 actions requires Australia to “pursue policies that are fully compatible with the treaty and the objective of achieving a world without nuclear weapons”. How is relying on nuclear weapons compatible with the objective of achieving a world without nuclear weapons?

The circle simply cannot be squared. Follow the tortuous reasoning to its conclusion and it reduces to “Australia supports nuclear disarmament, just as soon as it has happened”.

As the humanitarian initiative gathers momentum, and as a ban treaty looms closer, Australia’s policy will become increasingly untenable. It will soon have to choose: nuclear weapons – yes or no. If the answer is yes, the only honest course is to drop the pretence of working towards a world free of nuclear weapons and leave the NPT. If the answer is no, then there are policy challenges ahead – but overcoming them would put Australia on the right side of history.

Richard Lennane is a former United Nations disarmament official and Australian diplomat.